Mosquito Spraying: Where and why?

Resident Glenn Williams Jr submitted the following query to the group:

So…I took a snippet overlaying where Bergen County has sprayed for Mosquitos the last 4 times (2018-2021). And I mean…this is almost hilarious to see. I’m genuinely interested in hearing a reasonable explanation as to how this is even possible. Do the mosquitos stop in the middle of Votee park to play basketball? Do they only cross Route 4 in one area? I mean COME ON. lol. I mean I’m willing to listen, but this doesn’t make a lot of sense to me at all. 4 years?
At first glance, it certainly seems odd.
So I did two things.
  1. I called the county to get information (they have yet to call me back)
  2. I looked up the Environmental Resource Inventory (available here)

Bergen County Mosquito Control

Mosquito-Control is in Bergen County is handled by The Bergen County Mosquito Control Division, founded in 1914.

Website for The Bergen County Mosquito Control Division

As per the “Questions and Answers” section of their site:

What does the Division do?

Bergen County has been performing mosquito control since 1914. Mosquito-borne disease control and quality of life
assurance are the principal concerns of the Division. The statutory mandate of the Division is “To perform all acts which
in its opinion may be necessary for the elimination of mosquito breeding areas, or which will tend to exterminate
mosquitoes within the county.” The key to the Division’s activities is a comprehensive surveillance program. The
presence of a mosquito problem must be documented before any control measures can be initiated. Emphasis is
placed on the elimination of mosquito production habitat and the control of mosquitoes while they are still in the
aquatic stages of their development.

They also indicate that:

“If surveillance indicates that a nuisance level of mosquitoes is reached or disease is detected, a spray for adult mosquitoes may be applied by hand-held sprayers, truck-mounted sprayers, or from the air.”

What is an Environmental Resource Inventory

The ERI for Teaneck is a document that is prepared by the Township that includes “information on geology, topography, slopes, hydrology and water resources, soils,
flooding, wetlands, wildlife habitat, historic resources, regional planning, air, and climate change.”

As the report indicates, “Teaneck is defined by its waterways and water resources.

Water Tables

Mosquitoes breed in water.  As water tables rise, we see a corresponding rise in the population of these pests.  I do not know the correlation between sea-level rise and mosquito populations, but scientists have been studying this for quite a while.  See, e.g.:

Teaneck Topography

On page 132, you can find the Topography map for Teaneck.  This map indicates, via color-coding, where the highs and lows are (in terms of feet above sea level) of the township’s various elevations.

There are two areas in Teaneck with the highest elevations (about 150+ feet above sea level.  One is about 1/4 mile from the Hackensack River and the other is centrally located about 1.5 miles from the River and 3 miles from the Hudson.

Let’s superimpose the area of highest elevations of the central area on the spray map:

Does the elevation make a difference in mosquito populations?  I don’t know the answer to that.  But the bottom part of the overlay was sprayed, so I’m curious as to how it interacts.

One note — the map here indicates spraying between 2018 to 2021.

If you remove this year, this is the spray map:

And the 2018-2020 Map with topographical overlay for BOTH high sea-level areas:

In this map, both of the higher elevation areas are skipped (with some of the southern edge of both (contiguous to the neighboring area) getting sprayed.

Conclusions

I don’t have any.  I don’t have enough data.  I am at the point where I no longer have the requisite expertise to come to a conclusion nor the data points for a good guess.

But these are the data points of where I’d focus the inquiry.

Namely:

  1. Does topography correlate in a positive way with breeding?
  2. Does regular testing in this area yield significantly different results in terms of whole number of pests as well as disease?
  3. What areas are tested and when?
  4. What do data show over time?

But perhaps someone here is capable of picking up where I left off?

If so — please let us know in the comments.